Chemical mechanical polishing (CMP) is generally known in the art. For example U.S. Pat. No. 5,177,908 issued to Tuttle in 1993 describes a finishing element for semiconductor wafers, having a face shaped to provide a constant, or nearly constant, surface contact rate to a workpiece such as a semiconductor wafer in order to effect improved planarity of the workpiece. U.S. Pat. No. 5,234,867 to Schultz et al. issued in 1993 describes an apparatus for planarizing semiconductor wafers which in a preferred form includes a rotatable platen for polishing a surface of the semiconductor wafer and a motor for rotating the platen and a noncircular pad is mounted atop the platen to engage and polish the surface of the semiconductor wafer. Fixed abrasive finishing elements are known for polishing. Illustrative examples include U.S. Pat. No. 4,966,245 to Callinan, U.S. Pat. No. 5,823,855 to Robinson, and WO 98/06541 to Rutherford.
An objective of polishing of semiconductor layers is to make the semiconductor layers as nearly perfect as possible.
Current finishing elements and equipment can suffer from being costly to manufacture. Generally very complex mechanical equipment used when finishing semiconductor wafers. Complex, expensive, and bulky mechanical drives are generally used for generating polishing pad and wafer polishing motions. Also current finishing elements for semiconductor wafers generally have coextensive surface layers which can limit their versatility in some demanding finishing applications. Current polishing pads are generally larger than the workpiece being finished which consumes precious floor space in a semiconductor fab. Still further, current finishing apparatus are not capable of supplying a parallel finishing motion to finishing elements solely through magnetic coupling forces. Still further, current finishing apparatus are not capable of supplying multiple different parallel finishing motions to multiple finishing elements solely through magnetic coupling forces. Still further, current finishing apparatus are not capable of supplying multiple different parallel finishing motions to multiple different finishing elements solely through magnetic coupling forces. Still further, current finishing apparatus are not capable of supplying refining motion(s) to refining element(s) solely through magnetic coupling forces wherein the refining element(s) inside an enclosed refining chamber and the driving element is external to the enclosed refining chamber. Still further, current finishing apparatus are not capable of supplying a parallel finishing motion to refining elements solely through magnetic coupling forces while electrodeposition and/or electropolishing. Still further, a lack of the above characteristics in a finishing element reduces the versatility of the refining method(s) which can be employed for semiconductor wafer surface refining. Still further, current finishing pads can be limited in the way they apply pressure to the abrasives and in turn against the semiconductor wafer surface being finished. These unwanted effects are particularly important and can be deleterious to yield and cost of manufacture when manufacturing electronic wafers which require extremely close tolerances in required planarity and feature sizes.
It is an advantage of this invention to improve the finishing method for semiconductor wafer surfaces to make them as perfect as possible. It is an advantage of this invention to make refining elements and refining equipment with a lower cost of manufacture and reduce the mechanical complexity of the refining equipment and thus also reduce the cost of refining a semiconductor wafer surface or workpiece surface. It is a preferred advantage of this invention to develop refining apparatus and refining elements that can be smaller than the workpiece being refined. It is further an advantage of the invention to develop refining apparatus that are capable of supplying a parallel refining motion to refining elements solely through magnetic coupling forces. It is further a preferred advantage of the invention to develop current finishing apparatus that are capable of supplying multiple different parallel refining motions to multiple different refining elements solely through magnetic coupling forces. It is further a preferred advantage of the invention to develop current finishing apparatus that are capable of supplying a plurality of independent parallel refining motions to multiple different refining elements solely through magnetic coupling forces. It is further an advantage of the invention to develop current refining apparatus that are capable of supplying multiple different parallel refining motions to multiple different, independently controlled refining elements solely through magnetic coupling forces. It is further an advantage of the invention to develop current refining apparatus that are capable of supplying multiple different refining energies, actions, and/or parallel motions to multiple different, independently controlled refining elements. It is further a preferred advantage of the invention to develop current refining apparatus, refining elements, and refining capability that can add and remove material from the workpiece surface being refined. It is further a preferred advantage of the invention to develop current refining apparatus, refining elements, and refining capability that can add and remove material from the workpiece surface being refined using similar and/or identical drive elements. It is an advantage of the invention to develop a refining element which has a unique way of applying pressure to the unitary and/or a plurality of discrete refining surface(s) and to the workpiece surface being refined. It is an advantage of the invention to develop a refining element which has a unique way of applying refining energy or energies to the unitary and/or a plurality of discrete refining surface(s) and to the workpiece surface being finished. It is further an advantage of this invention to help improve yield and lower the cost of manufacture for finishing of workpieces having extremely close tolerances such as semiconductor wafers. It is further an advantage of this invention to help improve versatility and control which will in turn improve yield, reduce consumable costs, and lower the cost of manufacture for refining of workpieces having extremely close tolerances such as semiconductor wafers. Preferred embodiments accomplish one or more of the above advantages with a new structure and function in a new way to give the new and useful result.
A preferred embodiment of this invention is directed to a method for refining a semiconductor wafer surface comprising a step of providing a magnetically responsive refining element having a refining surface free of any physically connected mechanical movement mechanism; a step of providing a magnetic driving element having a driving mechanism; a step of positioning the semiconductor wafer being refined with a holder proximate to the magnetically responsive refining element and between the magnetically responsive refining element and magnetic driving element; and a step of applying an operative refining motion comprising a magnetically induced parallel operative refining motion in the interface between the semiconductor wafer surface being refined and the refining surface of the magnetically responsive refining element for changing the amount of material on the semiconductor wafer surface.
A preferred embodiment of this invention is directed to a method for refining a semiconductor wafer surface comprising a step of providing a magnetically responsive refining element having a first electrode; a step of providing a magnetic driving element operatively connected to a driving mechanism; a step of providing a semiconductor wafer surface having an operative electrical contact forming a second operative electrode between the magnetically responsive refining element and the magnetic driving element; a step of magnetically coupling the magnetically responsive refining element with the magnetic driving element; a step of applying a parallel operative refining motion between the semiconductor wafer surface and the magnetically responsive refining element by moving magnetic driving element with the driving mechanism; and a step of applying an operative electric field across the first operative electrode and the second operative electrode for electro-refining during at least the portion of a refining cycle time.
A preferred embodiment of this invention is directed to an apparatus for refining a workpiece surface comprising at least one magnetically responsive refining element free of any nonmagnetic driving mechanism; at least one magnetic driving element operatively connected to a driving mechanism and wherein the at least one magnetic driving element is spaced apart from the magnetically responsive refining element; and a holder for a workpiece which exposes the workpiece surface for refining, the holder situated between the magnetically responsive refining element and the at least one magnetic driving element and having an adjustable retainer ring.
A preferred embodiment of this invention is directed to a magnetic refining element comprising an operative electrode; a magnetically responsive member protected with a corrosion resistant material; and an operative electro-refining surface, and at least one material which connects the operative electrode, the magnetically responsive element and the operative electro-refining surface.
A preferred embodiment of this invention is directed to a method for finishing a semiconductor wafer surface comprising a step 1) of providing a magnetically responsive finishing element free of a nonmagnetic driving mechanism; a step 2) of providing a magnetic driving element operatively connected to a driving mechanism; a step 3) of providing a semiconductor wafer surface between the magnetically responsive finishing element and the magnetic driving element; a step 4) of magnetically coupling the magnetically responsive finishing element with the magnetic driving element; and a step 5) of applying an parallel operative finishing motion in the operative finishing interface formed between the semiconductor wafer surface and the magnetically responsive finishing element by moving magnetic driving element with the driving mechanism.
A preferred embodiment of this invention is directed to a method for finishing a semiconductor wafer surface comprising a step of providing a plurality of magnetically responsive finishing elements free of any physically connected movement mechanism; a step of providing a plurality of magnetic driving elements operatively connected to at least one driving mechanism; a step of providing a semiconductor wafer surface between the plurality of magnetically responsive finishing elements and the plurality of the magnetic driving elements; a step of magnetically coupling the magnetically responsive finishing elements with the plurality of the magnetic driving elements; and a step of applying an parallel operative finishing motion in the operative finishing interface formed between the semiconductor wafer surface and the plurality of the magnetically responsive finishing elements by moving the plurality of the magnetic driving elements with at least one driving mechanism.
A preferred embodiment of this invention is directed to a method of removing unwanted material from a semiconductor wafer surface comprising a step of providing a magnetically responsive finishing element having a finishing surface free of any physically connected movement mechanism; a step of providing a magnetic driving element having a driving mechanism; a step of positioning the semiconductor wafer being finished with a holder proximate to the magnetically responsive finishing element and between the magnetically responsive finishing element and magnetic driving element; a step of applying an operative finishing motion comprising a magnetically induced parallel operative finishing motion in the interface between the semiconductor wafer surface being finished and the finishing surface of the magnetically responsive finishing element in order to remove the unwanted material.
A preferred embodiment of this invention is directed to a method of refining a semiconductor wafer having a finishing cycle time comprising a step of providing a plurality of magnetically responsive finishing elements having a finishing surface free of any nonmagnetic driving mechanism; a step of providing a plurality of magnetic driving elements having at least one driving mechanism; a step of providing a control subsystem having at least one semiconductor wafer finishing sensor for providing finishing information; a step of positioning the semiconductor wafer being finished with a holder proximate to the plurality of the magnetic finishing elements and between the magnetically responsive finishing element and the plurality of the magnetic driving elements; a step of applying an operative finishing motion comprising a magnetically induced parallel finishing motion between the semiconductor wafer surface being finished and the finishing surfaces of the plurality of the magnetically responsive finishing elements; and a step of controlling in situ a control parameter with the finishing control subsystem after evaluating the finishing information.
A preferred embodiment of this invention is directed to an apparatus for refining a workpiece surface comprising a plurality of magnetically responsive refining elements free of any nonmagnetic driving mechanism; a magnetic driving means spaced apart from the plurality of the magnetically responsive refining elements; a holder for a workpiece which exposes the workpiece surface for finishing, the holder situated between the plurality of the magnetically responsive refining elements and the magnetic driving means, and wherein the magnetic driving means is for driving the plurality of the magnetically responsive refining elements in a parallel operative refining motion against the workpiece surface being finished.
A preferred embodiment of this invention is directed to an apparatus for refining a workpiece surface comprising a magnetically responsive refining element free of any nonmagnetic driving mechanism; a magnetic driving element operatively connected to a driving mechanism and wherein the magnetic driving element is spaced apart from the magnetically responsive refining element; and a holder for a workpiece which exposes the workpiece surface for finishing, the holder situated between the magnetically responsive refining element and the magnetic driving element and having an adjustable retainer ring.
A preferred embodiment of this invention is directed to an apparatus for refining a workpiece surface comprising a plurality of magnetically responsive refining elements free of any physically connected movement mechanism; a plurality of magnetic driving elements operatively connected to at least one driving mechanism and wherein the plurality of the magnetic driving elements is spaced apart from the magnetically responsive refining element; a holder for a workpiece which exposes the workpiece surface for refining to the plurality of the magnetically responsive refining element, the holder situated between the plurality of the magnetically responsive refining elements and the at least one magnetic driving element; and a refining control subsystem having an operative workpiece sensor and magnetically responsive refining element sensor.
A preferred embodiment of this invention is directed to a magnetic finishing element having a plurality of discrete finishing members for finishing a semiconductor wafer comprising a plurality discrete finishing members wherein each discrete finishing member has a surface area of less than the surface area of the semiconductor wafer being finished, each discrete finishing member has an abrasive finishing surface and a finishing member body, and a ratio of the shortest distance across in centimeters of the discrete finishing member body to the thickness in centimeters of each discrete finishing member body is at least 10/1; and at least one magnetic composite member has a corrosion resistant coating and the plurality of discrete finishing members is attached to the magnetic composite member.
A preferred embodiment of this invention is directed to a magnetic finishing element having a finishing layer with a finishing surface for finishing a semiconductor wafer comprising the finishing surface layer having a finishing surface area of less than the surface area of the semiconductor wafer being finished; and a magnetic composite member wherein the magnetic composite member is attached to the finishing surface layer and the magnetic composite member is protected with a polymeric corrosion protecting layer.
A preferred embodiment of this invention is directed to a magnetic finishing element having a finishing layer with finishing surface for finishing a semiconductor wafer comprising the finishing surface layer having a finishing surface area of less than the surface area of the semiconductor wafer being finished and a ratio of the shortest distance across in centimeters of the finishing surface layer to the thickness in centimeters of the finishing layer is at least 10/1, and a magnetic member wherein the magnetic composite member is attached directly or indirectly to the finishing surface layer.
Other preferred embodiments of my invention are described herein.
These and other advantages of the invention will become readily apparent to those of ordinary skill in the art after reading the following disclosure of the invention.